A mechanical transmission, for example as used in an all-terrain vehicle, may provide multiple gear positions, for example: high, low, neutral, reverse, and park, as are generally understood in the art. Often it is desirable to provide an electrical signal indicating the gear position, for example, to provide visual feedback to the user or as part of an electrically controlled gear shifting mechanism.
An existing sensor for providing this electrical signal indicating gear position uses a set of concentric electrical contacts arranged along arcs about a common center. These contacts may be manufactured as a lead frame insertion-molded into a plastic housing during an injection molding process. A wiper, movable with a gear selection shaft of the transmission, may connect and disconnect different contacts to provide switched signals indicating the gear position.
One drawback to the above design is the expense of producing a lead frame and insertion-molding the lead frame into the housing as well as the high tooling costs when changes in the sensor are required, for example, for different transmission models.
A second drawback to a switched sensor of the type described above is the need for multiple electrical wires to communicate between each of the different contacts and a remote circuit employing the gear position signal. This latter drawback can be addressed by employing a potentiometer that can be turned by the gear selector shaft to output a variable resistance that can be communicated over a single pair of wires instead of the multiple wires needed for multiple contacts. A potentiometer may provide a resistive trace along which a conductive wiper may travel to produce a varying resistance. Standard potentiometers may be insufficiently robust for the transmission environment and specialty potentiometers can require costly retooling when changes are required.